Investigation of Thin Liquid Films of Small Diameters and High Capillary Pressures by a Miniaturized Cell

• Published in: Journal of colloid and interface science 1995-10, Vol.175 (1), p.68-76
• Main Authors: Velev, O.D., Constantinides, G.N., Avraam, D.G., Payatakes, A.C., Borwankar, R.P.
• Format: Article
• Language: English
• Subjects: capillary pressure; Chemistry; Colloidal state and disperse state; dimple; Exact sciences and technology; General and physical chemistry; General, apparatus, technics of preparation; nonionic surfactants; protein-stabilized emulsions; thin liquid films
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.1995.1430

A highly miniaturized cell for the experimental investigation of thin foam and emulsion films has been constructed. The miniaturization of the structure in the new design is achieved by forming the cell out of thin glass slides drilled by excimer laser and sintered into a single structure. The capillary pressures and film dimensions attainable in our type of cell are closer to reality than those in the currently deployed models. Parallel experiments on the formation and thinning of emulsion films stabilized with nonionic surfactant (Tween 20) and with protein (BSA) have been carried out in the newly designed and in the conventional cell. The data reported in the paper show that the patterns and the time scales of film evolution in the two cells are significantly different. No dimple formation in the realistic films has been observed. A particularly drastic difference in the time scales is recorded in the case of protein-stabilized systems, probably resulting from the increased interfacial viscosity and elasticity.